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| author |   H.J. Lu <hjl.tools@gmail.com> | 2018-10-24 02:19:15 -0700 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2018-10-24 02:19:34 -0700 |
| commit | 7cc65773f04e0f4252428c40dcbb784a39b58cd1 (patch) | |
| tree | 8ab811df64ea1c81daac9b4e8b645ea3998acf08 /benchtests/Makefile | |
| parent | Fix tst-preadvwritev2 build failure on HURD (diff) | |
| download | glibc-7cc65773f04e0f4252428c40dcbb784a39b58cd1.tar.gz glibc-7cc65773f04e0f4252428c40dcbb784a39b58cd1.tar.bz2 glibc-7cc65773f04e0f4252428c40dcbb784a39b58cd1.zip | |
x86: Support RDTSCP for benchtests
RDTSCP waits until all previous instructions have executed and all
previous loads are globally visible before reading the counter. RDTSC
doesn't wait until all previous instructions have been executed before
reading the counter. All x86 processors since 2010 support RDTSCP
instruction. This patch adds RDTSCP support to benchtests.
* benchtests/Makefile (CPPFLAGS-nonlib): Add -DUSE_RDTSCP if
USE_RDTSCP is defined.
* sysdeps/x86/hp-timing.h (HP_TIMING_NOW): Use RDTSCP if
USE_RDTSCP is defined.
Diffstat (limited to 'benchtests/Makefile')
| -rw-r--r-- | benchtests/Makefile | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/benchtests/Makefile b/benchtests/Makefile index bcd6a9c26d..45aeb5febe 100644 --- a/benchtests/Makefile +++ b/benchtests/Makefile @@ -131,6 +131,12 @@ CPPFLAGS-nonlib += -DDURATION=$(BENCH_DURATION) -D_ISOMAC # HP_TIMING if it is available. ifdef USE_CLOCK_GETTIME CPPFLAGS-nonlib += -DUSE_CLOCK_GETTIME +else +# On x86 processors, use RDTSCP, instead of RDTSC, to measure performance +# of functions. All x86 processors since 2010 support RDTSCP instruction. +ifdef USE_RDTSCP +CPPFLAGS-nonlib += -DUSE_RDTSCP +endif endif DETAILED_OPT := |